A Queensland family were looking forward to lunch together when they heard their mother cry out and found her dying on the laundry floor, a court has heard.
The police initially thought Giustina Katerina Lawlor, 53, had died from a blood clot but a later scan found a bullet in her abdomen.
Mrs Lawlor's son, Cristian Dino Charles Lawlor, then aged 22, was charged with her manslaughter.
Lawlor told police he left a live round in the barrel of a firearm and then placed it in a bag in the garage of the family's home at Taigum in Brisbane's northern suburbs on May 7, 2021.
The next day Lawlor's mother picked up and moved the bag.
The antique and partially disassembled rifle was left in a state where a light bump could, and did, cause it to fire.
The bullet struck several of Mrs Lawlor's internal organs and she died in her husband's arms while surrounded by family members.
Lawlor faced Brisbane Supreme Court on Tuesday and pleaded guilty to the lesser charge of conduct with a weapon likely to cause death or injury.
He also pleaded guilty to unlawful possession of a firearm, ammunition and a telescoping baton as well as possessing methamphetamine and a drug pipe.
Crown prosecutor Clayton Wallis said Lawlor, now aged 24, had been restoring the family heirloom rifle despite having no real knowledge of guns.
"One of the poor choices he engaged in was restoring it to operability and another choice was storing it, albeit disassembled, in a bag (where) other people had access," Wallis said.
Wallis said the final poor choice Lawlor made was leaving a round in the firearm and that formed the basis for the charge of dangerous conduct with a weapon.
Lawlor's older sister read out her victim impact statement and said the case and resulting publicity had interrupted the family's ability to grieve for a loss that will be felt for their entire lives.
"I wish for today to be the last day that my brother is seen as a defendant and he is a victim and we can go out and live for our mother's name," she said.
Lawlor's barrister James Godbolt said the case was genuinely tragic and involved circumstances that were unique in many respects.
"My client's erroneous belief was that in its (disassembled) state it was incapable of being fired," he said.
Godbolt said Lawlor would seek treatment for drug and mental health issues if released on parole.
Justice Sue Brown said guns were not toys and Lawlor had engaged in serious offending but he had also shown significant remorse, and had co-operated with police and the justice system.
"Whatever sentence I impose upon you will fade into insignificance compared to the sentence you have placed on yourself," Brown said.
Lawlor was sentenced to two-and-a-half-years' imprisonment but released on parole immediately.
Brown urged Lawlor to look at a picture of his mother if he felt tempted to breach parole and ask himself what she would want.